Six Democratic presidential contenders took the stage for the final time before nominating contests start, and tensions cracked through a field that has resisted attacks for much of the primary race.
The rivals in the debate — former Vice President Joe Biden, Sens. Bernie Sanders of Vermont, Elizabeth Warren of Massachusetts and Amy Klobuchar of Minnesota, former South Bend, Indiana, Mayor Pete Buttigieg, and billionaire Tom Steyer — spent two hours at Drake University in the last debate before the first-in-the-nation Iowa caucuses.
Biden maintains a lead in national polls, but surveys in the Hawkeye State have found four candidates have a real chance to win the most delegates there on Feb. 3, and contenders used their last chance to distance themselves from their competitors.
The debate came amid tension between the two chambers of Congress as a Senate trial for President Donald Trump's impeachment looms next week.
At the same time, pressure has climbed in the Middle East, following Iranian retaliation for the U.S. killing of the country's top general, Qasem Soleimani. Secretary of State Mike Pompeo and Treasury Secretary Steven Mnuchin announced new sanctions last week on Iran's metal exports and eight senior Iranian officials.
Here are the night's top moments from Tuesday night's debate.
The contenders first faced questions about their credentials to handle the rising specter of war in the Middle East following the U.S. killing of Iran's top general, Qasem Soleimani, earlier this month. Candidates have tried to leverage their foreign policy records to garner support amid the sharpened focus on Iran.
Sanders defended his decision as a House member to vote for a military force authorization in Afghanistan, and again attempted to distance his record on Iraq from Biden's.
"I took to the floor, I did everything I could to prevent that war. Joe saw it differently," he said.
Klobuchar, asked whether she would remove forces from the Middle East, said she would "leave some troops there." Warren, meanwhile, contended that "we need to get our combat troops out." Buttigieg, an Afghanistan War veteran, criticized the president for sending more troops to the region.
Biden, when asked the same question, said he would leave troops in the Middle East if he became president, adding that "we're in a position where we're going to have to pull our forces out" because of the U.S. decision to kill Soleimani.
"Frankly I think [Trump] flat-out lied" about the reason the president authorized the strike, Biden said.
One of the night's biggest laughs came from Sanders as Biden aimed to contrast his foreign policy vision from Trump's.
Asked whether he would meet with North Korean dictator Kim Jong Un, the former vice president said he would not without preconditions. Trump has held two summits with Kim as he pushes Pyongyang to abandon its nuclear and missile programs — which Biden said gave North Korea the legitimacy it wants.
"I would not meet with the, quote, supreme leader who said, 'Joe Biden is a rabid dog, he should be beaten to death with a stick,'" Biden said, citing a comment last year from North Korea's state news agency.
"Other than that, you like him?" Sanders interjected, about the ruler whose regime stifles free expression and opposition and carries out executions. Laughter broke out in response.
"Other than that, I like him, and he got a love letter from Trump after that," Biden responded.
Progressive rivals Warren and Sanders sparred over their trade policy.
While most Democrats vying to defeat Trump have criticized his protectionist trade policies and trade war with China, Warren and Sanders have said they are open to using tariffs in some ways.
And while Democrats and Republicans alike have championed the U.S.-Mexico-Canada Agreement as a beneficial update to the North American Free Trade Agreement, Warren and Sanders have been more critical of it.
Still, both carved out distinctions between their policies on the debate stage Tuesday night. Warren has said she would vote for the USMCA.
Sanders said he would refuse, noting the lack of support for the deal from environmental organizations.
"Every major environmental organization has said no to this new trade agreement because it does not even have the phrase 'climate change' in it," he said.
Warren, however, said the USMCA "will give some relief" to U.S. farmers and workers. "I believe we accept that relief, we try to help the people who need help, and we get up the next day and fight for a better trade deal."
Sanders responded that retooling existing trade deals is no easy task. "I believe if this deal is passed, it will set us back a number of years," he said.
The strength of female candidates became a topic of discussion after a day of controversy over Warren's claim that Sanders had told her in a private meeting before she announced her White House bid that a woman couldn't win the presidency.
Sanders denied that he said it, pointing to his record and a video on YouTube as evidence.
"Anybody who knows me knows that it's incomprehensible that I would think that a woman could not be the president of the United States," Sanders said.
The Vermont senator, who identifies as a democratic socialist, added that in 2015 he chose to hold off on announcing his candidacy for president, until Warren told him she would not run in the 2016 election.
She also pivoted away from her private conversation with Sanders, instead choosing to focus on the records of the women on stage.
"Look at the men on this stage," Warren said. "Collectively they have lost 10 elections. The only people on this stage who have won every single election that they've been in are the women. Amy and me."
Sanders and Warren's reputed friendship has been tested as the campaign heated up, particularly after the reports about the issue of a woman's electability.
Things appeared to reach a head immediately after the debate as Sanders sought to shake Warren's hand. While Steyer looked on, she did not reciprocate. Instead, Warren and Sanders appeared to exchange some terse words, although it wasn't clear what they said to each other. Sanders turned away in a huff.
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